HELP!!! WEAK BRAKES!

Ok, I've been having brake issues for a while. Started with sticking front calipers causing a left pull under hard brake. Just replaced the calipers and lines with braided SS lines from Wheelers. Rear line also replaced. All fluid exchanged and brakes bled. Rotors, drums, pads, and shoes replaced within the past 2 years. Current issues I have is still an occasional left pull under braking. Also, sometimes I drive the truck, and the brakes are awesome when I initially start driving. It seems to brake very well and you can feel them engage almost as soon as you touch the petal. The SS lines have made the pedal much stiffer. After driving for a little while, I notice the pedal getting softer and farther down each time I brake until I have almost no power. It has done this to me twice when I had to stop in rain for a red light and the truck wouldn't stop. The front locked and I started sliding, and the only way I could stop is pull the ebrake. This has almost killed me twice, and the last time I had a sibling in the truck, and I need suggestions. Help please.

 

Either your abs is screwing up in the rain or you have bleeding brakes not sure how abs works but heard it's a pain in the ass on our trucks

 

I have no ABS. I'm a first gen and my truck doesn't have the option

 

No clue but maybe it's time for a new brake booster? Keep in mind I am probably totally incorrect.

 

Oh then bleeding brakes? Have you checked the drums in the rear?

 

From what I've researched, a bad brake booster will make the pedal extremely hard

 

They were just bled out when I changed the lines and the drums and shoes were done 6 months ago

 

Bump

 

Did you use OEM brake parts? They work better than most aftermarket stuff.

If the pedal feel is getting soft, with more travel, I'd suspect the brake master cylinder.
If the front is locking up too quickly, then checkout the LSPV near the rear axle.

 

It's good braking at first. The pedal is firm and braking is good. Then as I drive it gets worse and the pedal gets softer, travels farther, and I lose all braking power. All the stuff I used was wearever brand from advanced auto

 

This one may be for a tech to fix. If the brakes were that iffy in my truck I'd take it in. I just did rear shoes and drums. OEM for both parts. I had issues with Brakebest from Oreilys. If no leaks are apparent and you have correctly installed pads, rotors, shoes, and drums AND lines, I'd say start looking at the master cylinder. The LSPV could be needing adjustment, but my bet with soft pedal is the booster.

 

I'd check those rear brakes. Saw this in son's mustang a couple of years ago. Reached the point driving where he could not move. Pedal got softer and softer, then brakes started dragging. Rear caliper had stuck. As it heated the fluid up, bubbles would form and the pedal got spongy. As it heated up more, fluid boiled and locked all the brakes up tight. The left pull sounds like your left brake might be dragging and getting hot, or your right front might be dragging and then fading due to heat. Drive a few miles, slow down and pull over staying off the brakes, and feel each hub. If one is super-hot, you've probably found the culprit.

Sometimes it is something as simple as getting the caliper wet and water getting behind the seal causing rust to form. That interferes with the piston retracting properly, keeping excessive pressure on the pads.

 

^^^ This is awesome advice. If you happen to have access to an IR thermometer even better. I accidentally tore a seal on a caliper and have been waiting for similar issues. Fingers crossed, I keep checking for uneven wear on the front right.

 

My first car (probably my favorite) was a 1968 Hemi Roadrunner. My second was a 1972 340 Dodge Challenger. About 2 years after we bought it the brakes were beginning to feel weak (this was the early days of disc brakes). Visited my mom/dad that weekend and my dad and I jacked it up (i had bought pads assuming that was the problem). We took a caliper off and tried to retract the piston. Nothing doing. Looking closer, NO "dust seal/water seal in sight. Checked other front caliper, same thing. We had to crank it up, put a block of wood in each caliper, and used the power brakes to force the calipers out. Massive rust. Cleaned them up with good old crocus paper, then new o-rings and seals and we drove it another 4 years with zero problems. The tolerance between caliper and piston is very tight.

My Son's problem was a known caliper pin problem where they would get corroded (the dust boot was basically worthless) and then cause the caliper to stick.

When I started towing a boat, I got used to the drill of checking the trailer wheels after a few miles, to pick up on a wheel bearing problem before it because a wheel bearing failure. I started doing the same to my truck and have not had any problems since.

 

All my brakes are new, including fluid. I just put new calipers on. I had a sticking right caliper, and I think it's glazed my pads and rotor, causing the left side to grab better then the right, making a pull. The other I think it's either a booster or master cylinder issue. It's in the shop today, we will see.

 

Had air still in the rear. I didnt realize there was 2 lines going to the rear proportioning valve and a bleeder on the valve itself. Pedal is firm and consistent now. I still feel like I have great power but it doesn't grab the brakes like it should. My mech thinks I have decent brakes, but he suggested I try new rotors and pads(I think they may be glazed). Just sucks cause these pads and rotors are about 2 yrs old and have a lot of life left

 

For what it's worth - I had brake issues with a 89 4runner that sound similar. They worked fine in normal use, but were terrible when braking hard. Felt like they just did not grab the rotors properly during emergency braking.... I had everything checked, bled etc. Everything was fine mechanically. Friend of mine recommended to change the pads, even though they had a lot of life left. As a last ditch effort I replaced the aftermarket front pads with OEM pad and brakes and - they worked like new. May or may not be the case for you, but for my truck the difference was night and day.

 

Thinking about doing this. It's still pulling left(I think my right pads/rotor is glazed causing the left to grab more) and I can now tell I have some warping starting cause there's some brake vibration. My pads and rotors are Wearever from Advanced Auto and I've heard some of these auto store brand pads and rotors are cheap and made from bad quality materials. The issue I had as far as the fading was due to there still being are in the rear. I was losing my rear brakes